How the Standard Deduction Calculation Works
The 2026 standard deduction has up to four components stacking on the base amount. For full statutory rules, examples, and the comparison with itemizing, see our Standard Deduction Guide.
Layer 1: Base Standard Deduction under IRC §63(c)(2) Confirmed
Set by filing status. For 2026: Single / MFS = $16,100; MFJ / QSS = $32,200; HOH = $24,150. These amounts reflect Rev. Proc. 2025-32 inflation adjustments under IRC §63(c)(4)(B), applied to the post-OBBBA base from P.L. 119-21 §70101.
Layer 2: Age and Blind Add-Ons under IRC §63(f) Confirmed
For each qualifying condition (taxpayer 65+, taxpayer blind, spouse 65+ on joint return, spouse blind on joint return), add the add-on amount. 2026: $1,650 per condition for married filers; $2,050 per condition for unmarried filers. 2025: $1,600 / $2,000. Conditions are independent and stack additively.
Formula: Add-ons total = (count of qualifying conditions) × (add-on per condition for filing status).
Layer 3: Dependent Override under IRC §63(c)(5) Confirmed
If the taxpayer can be claimed as a dependent on another return, the standard deduction is reduced to the greater of (a) $1,350 (2025 and 2026) OR (b) the dependent's earned income plus $450, capped at the regular standard deduction for the dependent's filing status. Age and blind add-ons under §63(f) still apply on top of this floor.
Formula: Dependent floor = max($1,350, earned income + $450), capped at regular standard deduction. Then add §63(f) add-ons.
Layer 4: OBBBA §70103 Senior Bonus (TY2025-TY2028 Only) Confirmed
Per P.L. 119-21 §70103, an additional $6,000 above-the-line deduction is available per eligible person age 65 or older, applicable for tax years 2025 through 2028. Phase-out begins at $75,000 MAGI (single/HOH) or $150,000 MAGI (MFJ), at $60 per $1,000 of MAGI excess. Fully eliminated at $175,000 (single/HOH) or $250,000 (MFJ). MFS ineligible.
Per-person phase-out formula: Reduction = floor((MAGI − Threshold) ÷ 1,000) × $60 | Senior Bonus = max(0, $6,000 − Reduction).
Critically, the OBBBA $6,000 senior bonus applies regardless of whether the taxpayer takes the standard deduction or itemizes - it operates as a separate above-the-line benefit (claimed on Schedule 1-A). The age and blind add-ons under §63(f), in contrast, apply only when taking the standard deduction.
Married Filing Separately §63(c)(6) Coordination Rule
Under IRC §63(c)(6)(A), if one MFS spouse itemizes, the other MFS spouse's standard deduction is reduced to zero. This is the "all-or-nothing" MFS rule: both spouses must elect the same path (both standard, or both itemize). The rule does not apply to MFJ or to spouses qualifying as HOH under §7703(b).
Total Deduction Formula
Total = (Base OR Dependent Floor) + §63(f) Add-Ons + OBBBA $6,000 Senior Bonus (if eligible). For itemizers: Total = Itemized + OBBBA $6,000 Senior Bonus (if eligible).